Electropneumatic brake



Jan. 7, 1930. Mfc, ROWLEY 1,742,415

ELECTROP NEUMATIC BRAKE Filed M 15. 1928 INVENTOR MILLARDC. ROWLEY BY Ml) ATTORNEY Patented Jan. 7, 1930 UNITED STATES PATENT OFFICE:

MILLARID o. nowLEY, or WILLIAMSPORT, PENNSYLVANIA, AssIeNoR ro r mINGHOUSE AIR BRAKE eoMrANY, or W'ILIVIERDING, PENNSYLVANIA, A CORPORA-TION OF PENNSYLVANIA ELEo'rRorNEUMAT o BRAK Application filed May 15,1928. Serial No. 277,880.

This invention relates to electro-pneumatic brakes and has for itsprincipal object to provide an improved electropneumatic brake equipmentwhich may be controlled either electrically or pneumatically.

Another object of my invention is to provide a brake equipment of theabove type in which the brakes may be pneumatically released after anelectric application and whlch may then be operated pneumatically.

A further object of my invention is to provide a brake of the abovetype-with means for preventing fluid under pressure from the brakecylinder from overcharging the auxiliary reservoir when the brakeequipment is changed from electric to pneumatic control.

These and other ejects will appear in the following more detaileddescription ofmy vice 3 is provided having a contact terminal 4 which isconnected to one terminal of a battery 5 or other electric currentsupply source,

a contact terminal 6 connected to one terminal of the magnet 1, and acontact terminal 7 con nected to one terminal of the magnet 2.

In the running and release position of the brake switch device 3, thebattery 5 is connected, by a connector '8, so as co-complete a circuitthrough both magnets land 2 and ground, thus energizing said magnets. Inthe lap position of the brake switch, the battery 5 is connected, by aconnector 9 so as to complete a circuit through the magnet 2 and ground,thus energizing said magnet.- In the service position of the switch, thebattery is, connected, by a connector 10, so as to complete a circuitthrough themagnet 1 and ground, thus energizing said magnet. In theemergency position of the switch the battery circuit isopen so that bothmagnets are de-.

energized.

'The magnets 1 and 2 are associated with an electropneumatic valvemechanism having I a pneumatic portion or triple valve device 11, anauxiliary reservoir 12, a change-over valve device 13, a changeoverpilot valve device 14, a service brake cylinder limiting valve device15, a check valve device 16, adouble check valve device 17, a brakecylinder 18, a mainireservoir '19, a relief valve device 20, and a brakepipe 21. 1

The triple valve device 11 may be of any desired type and as shown inthe drawing.

may comprise a piston 22 contained in a piston chamber 23, which chamberis connected to the brake pipe 21 by passage 24, graduatlng springchamber 25 and pipe 26. A main .slide valve27 anda graduating slidevalve 28, contained in a valve chamber 29, are

adapted to be operated by the piston 22,- the valve chamber 29 beingconnected to theauxihary reservoir 12 through passage and P p 0- a I Thechange-over valve device 13 comprises connected pistons 31 and 32contained in respective piston chambers 33 and 34 and a slide valve 35contained in a valve chamber 36 and adapted to be operated by saidpistons.

The change-over pilot valve device 14 may comprise spaced flexiblediaphragms 37 and 3 8, the area of the diaphragm 37 being greater thanthat of the diaphragm 38. Contained in the chamber 39 between thediaphragms 37.

and 38 is a follower member having a plate 40 secured. to the diaphragm37 and having av stem 41 secured to the diaphragm 38, which diaphragmsare adapted to operate double beat valves 42 and 43, the valve 42 beingcontained in a valve chamber 44 at one side ofthe diaphragm 38, whichchamber is connected, at all times, to I atmosphere through anatmospheric passage 45. The chamber 39 is connected tothe chamber 46 bya restricted'passage 47, and both chambers 39 and 46 areconnected to thebrake pipe 21 through apassage Y and pipe 48 and pipe 26.

The service brake cylinder limiting valve device 15 comprises a piston50 contained in a cylinder 51. The chamber 52 at one side of the piston50 is open, at all times, to atmosphere through passage 54, which;chamber with the chamber 58 at oneside of the piston The chamber 58 isconnected by a passage 59 to a chamber 60 containing a check valve 61adapted to seal against a seat ring 62 and also containing a spring 63,the pressure of which spring tends to maintain the check valve seated.This passage 59 is connected to a passage 64 leading to the seat of theslide 7 valve '35 of the change-over valve device 13.

c The magnet 1 is adapted to control the operation of double beat valves65 and 66 contained in a valve chamber 67, while the magnet 2 is adaptedto control the operation of double beat valves 68 and 69 also containedin the valve chamber 67, which chamber is,

connected to the chamber 33 of the changeover valve device 13 by apassage 70. Beneath the valve 66 is a chamber 71 from which a passage 72leads on the inner seated area of the check valve 61.

The main reservoir 19 is connected to a chamber 73, beneath the valve69, to the slide valve chamber 36 of the changeover valve the relayvalve 43 by pipe and passages 75. The double check valve device 17comprises a cylinder containing a check valve 76, the

chamber 7 7 at one side of the valve being connected to a pipe andpassage 78 leading to the seat of the slide valve 35 of the change-overvalve device 13. The chamber 79 at the other side of the check valve isconnected through a pipe and passage 80 leading to the seat of the mainslide valve 27 of the triple valve device 11. The check valve -7 6 isoperative at one time to connect the chamber 77 to the brake cylinder 18through a port 81, passage 82 and pipe 83, and is operative at anothertime to connect the chamber 79 to the brake cylinder through a port 84,passage 82 and pipe 83.

The relief valve device 20 is connected to the pipe 80 intermediate thetriple valve device11 and the doublecheck valve device 17 and maycomprise a valve 110 contained in a valve chamber 111 which is vented tothe atmospherethrough a passage 104. Contained inthe chamber 111 is aspring112 tending to maintain the valve seated. Leadingfrom the pipe 80to the seated area of the valve 110 is a pipe and passage 113. V

For the purpose of-controlling the pneumatic operation of the brakes, abrake valve device 85 may be provided whichmay be of the usual type andwhich is shown diagrammatically inthe drawing; In its running po-.

tion, the brake pipe 21 is charged with fluid under pressure from themain reservoir 19 through pipes 75-a'nd 88, teed valve 86, pipe 87 andbrake valve device 85, and fluid under pressure 1s supplied from thebrake pipe to the piston chamber 23 of the triple valve device 11through pipe 26, chamber 25 and passage 24, moving the piston 22 to itsnormal release position, as shown in the drawing In this position, fiuidis supplied from the piston chamber 23 to the valve chamber 29 throughtheusual feed groove 89, and from i said valve chamber to the auxiliaryreservoir 12 through passage and pipe 30. The diaphragm chamber 46 ofthe change-over pilot valve device .14 is also supplied with fluid underpressure from the brake pipe through pipe 26 and pipe and passage 48,and from said chamber46to the chamber 39 through the restricted passage47. \Vhen the pressures on both sides of the diaphragm 37 becomesubstantially equal. ,the pressure of fluid in chamber 39 acts on thesmall diaphragm 38 and 7 moves it upwardly, seating the valve 42 anddevice 13 and to the chamber 74 containing v unseating the relay valve43.

iVhcn the brake switch is in runnmg and release position, bothmagnets 1and 2 are energized so that valves'65 and 68 are held unseated-and thevalves 66 and 69. seated so that the chamber 67 is vented to theatmosphere past the unseated valve 68 and through an atmospheric passage90, and as the piston chamber 33 is connected to the chamber 67 bypassage said chamber 33 is maintained at atmospheric pressure. The brakecylinder 18 is also maintained at atmospheric pressure by reason of itsconnection to the chamber 67 through pipe 83, passage 82 of the doublecheck valve device 17, port 81, valve chamber-77, pipe and passage 78, acavity 91 in the slide valve 35 of the change-over valve device 13,passages 64'and 59, piston chamber 58, past the normally openvalve 56,valve sure from the main reservoir 19 is supplied.

to the chamber 73 beneath'the valve 69 and the valve chamber 36 of thechange-over valve device 13, by way of pipeand passage 75. The pistonchamber 34 of the changeover value device is supplled with fluid underpressure from the passage through valve 1 chamber 74, past the unseatedrelay valve 43 and through a passage 96; As the piston chamber 33 isvented to the atmosphere the pressure of fluid in piston chamber 34acting on the face of the piston 32 will maintain both pistons and slidevalve 35 in their normal positions,-'as shown in the drawing, in

which position of the slide valve, thebrake cylinder 18 is vented to theatmosphere as ergized, fluid under pressure in the chamber 7 3 suppliedfrom the main reservoir 19, through pipeand passage 75, will cause thevalve 69 to unseat and the valve 68 to's'eat, the seating ofthe valve 68closing off communication of the chamber-with the atmosphere by way ofthe atmospheric passage 90. Since the magnet 1 is energized, the valve66 willbe seated and the valve65 unseated, so

that fluid under pressure flowing past the unseated valve 69 will flowpast the unseated valve 65 to the brake cylinder 18 through passage 95,valve chamber 94, a restricted passage 97, passage 92, valve chamber 57,past the open ball valve 56 into the piston chain ber 58 of the servicelimiting valve device and from thence through passages 59 and 64, cavity91 in the slide valve 35 of the changeover valve device, passageand pipe78, valve chamber 77 of the double check valve device,

port 81, passage 82 and pipe 83. It will-be noted that fluid underpressure is also supplied to the piston chamber 33 of the changeovervalvedevice by way of'passage 70, but

so long as the pressure is maintained on the face of the piston 32, thechange-over valve:

device is maintained in its leftfhand position, asshown in the drawing.

If it is desired to effect a full service appli cation of the brakes,the brake switch 3 is maintained in service position, and when apredetermined brake cylinder pressure has been attained, the pressure offluid in the chamber 58 will cause the pistonf5O of the limiting valvedevice 15 to'move downwardly against the pressure of the spring 53 Asthe piston moves downwardly, the stem moves with itout of supportingengagement with the ball valve- 56 and permits the valve toseat, thusclosing off thefurther supply of fluid under pressure to the brakecylinder.

Should it be desired to effect a service application of the brakes, lessthan a full service application, the brake switch is held in serviceposition until the desired brake cylinder pressure is attained, whenthe, brake switch is moved to lapposition, in-which po sition the magnet2 is energized and themagchamber 77 of the net 1 deenergized.The'energization of the magnet 2 operates to seat the valve 69, so thatfurther flow of fluid under pressure to the valve chamber 67 is cut oil,and operates to unseat the valve 68, so that fluid under pressure inthis chamber is vented to the atmosphere through the atmospheric passage90. Upon the deenergization of them'agnet-l, the pressure of a'spring 98will cause the valve 66 to unseat and the valve to seat; The seating ofthe valve 65 prevents the flow of fluid under pressure from thepassage95 to the chamber 67, while the seated checkvalve 61 prevents theflow of fluid to the chamber I 67 by way of the passage 7 2. and-chamber71, thus it will be noted that the, fluid pressures in the brakecylinder is bottled up;

If it is desiredjto releasethe brakes,;thef brake switch is moved torelease position in which both of the magnets the running and,

1 and 2 are energized so that the valves "65 a and 68 are unseated andthe valves 66- andg69- are seated. Fluid under pressure in the brake fcylinder 18 is then vented to the atmosphere through pipe 83,

and passage'78, cavity 91 of the slide passage 82, port 81, valve checkvalve, device 17, pipe valve of the change-over valve device 13,passages 64 and 59, piston chamber 58 of the service brake cylinderpressure limiting 'valve de-.

vice 15. raisingithe ball valve 56 and through valve chamber 57, passage72, raising the check valve 93, then through valve chamber 9.4,passage95, past the unseated valve '65, i

through the atthrough valve chamber 67, past the un seated valve 68 and-finally mospheric passage 90. When the brake cylin der is thus vented,pressure of the spring. 53

will cause the piston 50, of the service brake cylinder pressurelimiting valve device, as well as the piston stem 55 to moveupwardly totheir normal positions, thus normally main-l taining the valve 56unseated. e

To effect an emergency application of the. "brakes, the brake switch 3is moved to emergency position, in which position, both magnets land 2are deenergized, so thatthe valve pressure of the spring 98, 1

66 will,'due to the be unseated and fluid under pressureflowing from themain reservoir 19 through pipe and passage 75 and chamber 73, willunseatthe valve 69 and seat the valve 68, the seating of the valve '68 closingoff communication from ,thechamber 67 to the atmospherethrough thepassage 90. 'Fluid under pressure'flows past the valve 66 into valvechamber 67 past I the unseated valve 66 to chamber 71 and from thencethrough passage 72 to the inner seated area of theicheck valve 61.'The'pr'essur'e of v the fluid n passage 2 causes the check valve 61 tobe unseated against 't-hepre'ssure of the spring 63, so that fluid underpressurethen flows through chamber 60 and from thence throughpassage '59and 64 to thebrake cylinder 18 in the same manner as in effecting a"service application of the brakes. It will herebe'noted that ineffecting an emergency application of the brakes the flow of. fluidunder pressure to the brake cylinder is sub:

stantiallyunrestricted, whereas in a service brake switch is moved torunning and release position, inwhich both of the magnets 1 and 2 willbedeenergized, causing the apparatus to operate to release the brakes inthe same manner as has been described in connection with-the release ofan electric service application of the brakes.

If, at anytime and or any reason, the electric current supply shouldfail, both magnets 1 and 2 will bedeenergized and an electric emergencyapplication will be effected" automatically in the samemanner as whenthe magnets are deenergized by moving the brakejswitch to emergencyposition.

WVhen an emergency application of the brakes has been effected dueto'thefailure of the electric current supply, the brake switch 3 will, ofcourse, be useless in controllingthe release of the brakes and in orderto release them, the hrake valve 85 isused. In a case of this kind thebrake valve is first moved to service position, in which the brake pipe21 is vented to the atmosphere through the cavity 99 in the usual rotaryvalve of the brakevalve device 85, and then through the atmosphericpassage 100, thus effecting a reduction in brake pipe pressure. Thisreduction in brake pipe pressure operates to cause the'pressureof fluidin the diaphragmchamber 46 of the pilot valve device 14 to reduce, sothatthe pressure of fluid in the chamberr39 acting on the flexiblediaphragm 37 causes both diaphragms 37 and 38, follower Y40, and stem 41to move downwardly, thus unseating the pilot valve 7 42 and permittingseated by the pressure of a. spring 102 conthe relay valve 43 to betained in the valve chamber 74. By the seating 'of the valve 43. fluidat mainreservoir pressure is cut oil from the piston chamber P 34 of thechange-over valve device, and by the unseating of the pilot valve 42permits fluid under pressure in this chamber to flow to'the atmospherethrough passage96, diaphragm chamber 44, and atmospheric passage 45'.Now as there is fluid under main reservoir pressure in the pistonchamber 33 acting on the faceof the piston 31 of the change-overvalvedevice, both pistons 31 and 32 and the slide valve 35 will movetotheirlright hand ositions', in which, the brake cylinder is vented tothe atmospherethrough pipe 83, passage 82,'port-81,1valve chamber 77 ofthechec r valve device 17, pipe and passage v78,--cavity 91 in the slidevalve 35 and atmospheric pass sage 103. "-It will here be noted afterthe connected pistons 31 and 32 and slide valve 35 have moved to theirright hand positions,

fluid under pressure in the diaphragm chambers 39 and 46 of the pilotvalve device will equalize through the restricted passage 47 andthe'pressure of fluid in the chamber 39, acting upon thesmall diaphragm38, causes the pilotvalve 42'to seat and the relay valve 43 to unseat,thus supplying fluid under pressure from the chamber 74 to the chamber34. This reduction in brake pipe pressure also operates to cause thetriple valve piston 22, graduating slide valve 28 and main slide valve27 to move toward the right to theirservice positions, in whichpositions a port 101 in the main slide valve connects the valve chamber29 to the passage 80, so that fluid under pressurefrom the auxiliaryreservoir 12 will flow through pipe and passage 30, valve chamber 29,port 101, passage and'pipe 80 to the valve covering the port 84 andconnectingthe brake cylinder 18 with the auxiliary reservoir throughthepipe 83, passage 82, port 84, valve chamber 79, pipe 80 and triple valvedevice 11.

\Vhen the bralze cylinder 18 and the auxiliary reservoir are thusconnected, the pressures therein equalize, and as the relief valve isset to operate at a predetermined degree below the normal brake pipepressure, the

valve 110 of the'reliet valve device will be' caused to unseat, so'thatfluid under pressure from the pipe 80 will flow to the atmospherethrough pipe 113, past the unseated valvellO,

and through valve chamber lllfand atmospheric passage 104. The valve 110remains unseated and'fluid under pressure flows to the atmosphere untilthe equalized pressure i s re-. duced to a predetermined degree belowthe.

normal brake pipe pressure when the pres sure ofthe spring 112 willcause the valve 110 to seat, closing off further flow to the atmos here,The brake valve device 85 maynow be moved to running and releaseposition so as to recharge the brake pipe 21 and release the" brakes inthe usual manner. V

It will here be notedthat if therelief valve device 20 were omitted,,thebrakescould not be released pneumatically after an-electric emergencyapplication, for the reasonvthat pressure of fluid in the brakecylindeiy'which has beensupplied from the main reservoir is greaterthanthat in theauxilia'ry reservoir 12, which has been suppliedfrom; thebrake pipe 21, and when the check valve 76 is; moved to the left, thepressure of the fluid inthe' brake cylinder would flow to the auxiliary:reservoir and overcharge it, with the result that in recharging thebrake pipe a suflicient.

differential could not be built up on the face of the triple valvepiston 22 to cause it tomove to release position against the equalizedpressure of the auxiliary reservoir and brake cylinder.

If it is desired to release the brakes pneumatically after anintentional electric emergency application, the brake switch 3 may bemaintained in emergency position and the release by the manipulation ofthe brake valve 85 will be the same as described in connection with therelease of the brakes after'an unintentional emergency application ofthe brakes. After an electric service application of the brakes or whenthe brake swltch is in lap position, the brakes may be releasedpneumatically in the same manneras described in connection withthe'release of an emergency application. V

Should it be desired to control the brakes electrically after they havethus been released pneumatically, the brake switch 3 is moved torunning'and release position, thus energizing both magnets 1 and 2,causing the valves 66 and 69 to seat and the valves and 68 to unseat.With the valve 68 unseated, fluid under pressure in the pistonchamber 33of the'chan'ge-over valve device will be vented to the atmosphereand'the pressureof fluid in the piston chamber 3 1, supplied fromthemain reservoir 19, will cause the connected pistons and slide valve v35tomove to their left hand positions, in which the'cavity 91 in the slidevalvewill again connect passages (i l and 78. Now when an application ofthe brakes is eflected, thefpressure of fluid flowing through thepassage and pipe 7 8 will causerthe check valve 76 to'mo've againto itsright handposition. e

With the switch 3 in running and release position the change-overpistons and slide valve will be in-thei-r left hand positions, so. thatwhen the triple'valve device is shifted to service position by effectinga reduction in brake upa-pressure 1n the-usual manner, the service port101 in the slide valve 27 registers with the "passage 80and fluid underpressure issupplie'd from the auxiliary reservoirv and valve chamber 29to passage and pipe 80 to the check valve chamber 79, causing the checkvalve 76 tomove toleft hand position and fluid under pressure in thechamber flows therefrom to the brake cylinder through port 8a, passage82 and pipe 83.

In the release position of the slide valve 27 the passage-8O isconnected to the atmospheric passage 106 by the cavity 107 in the slidevalve.

In an emergency application as efl'ected pneumatically, the movement ofthe slide valve 27 to emergency position causes the passage 108 toregister with the passage 80,

- plying fluid at alower pressure to said brake cylinder, valve meansadapted in one position to establish communication through which fluidis supplied to the brake cylinder from theflrst mentioned source andadapted in another position to establish communication through whichfluid under pressure is supplied to the brake cylinder from the second'mentioned source, and means for reducingthe equalized brake cylinder andsecond mentioned fluid pressure supply source to a predetermined degreebelow the normal pressure of the second mentioned supply source whencommunication of the second mentioned supply source and brake cylinderis established after fluid under pressure has been supplied to the brakecylinder from the first mentioned supply source. V

2. Ina braking apparatus, the combination Witha brake cylinder, ofelectrically controlled means for supplying fluid under pressure to thebrake cylinder, pneumatically pressure to the brake cylinder, a brakepipe for supplying fluid under pressure to said pneumatically controlledmeans, valve means adapted in one position to establishcommunicationthrough which fluid under pressure is supplied to the-brake cylinder byoperation of the electrically controlled means and adapted in anotherposition to establish communication through which fluid under pres sureis supplied to the brake cylinder by operation of the pneumaticallycontrolled means, andmeans operative to reduce the equalized pressure offluid from the brake cylinder and "the pressure of fluid supplied by thepneumatically controlled means below the normal pressure of fluid in thebrake pipe when communication is established between said brake cylinderand pneumatically controlled means.

3. In a braking apparatus, the combination with a brake cylinder, ofelectrically controlled means for supplying fluid imder pressure to thebrake cylinder, pneumatically controlled means for supplying fluid underpressure to the brake cylinder, a brake pipe for supplying fluid underpressure to said pneumatically controlled means, valve means adapted inoneposition to establish communication through which fluid underpressure supplied to the brake cylinder by operation of the electricallycontrolled means and adapted in another positionito establishcommunication through which fluid under pressure is supplied to thebrake cylinder by operation of the pneumatically controlled .means, anda valve device operative to reduce, to a predetermined degree, theequalized I pressure of fluid from the brake cylinder and r the pressureof fluid supplied by the pneumatically controlled'means whencommunication is established between said brake cylinder andpneumatically controlled means.

4. In a braking apparatus, the COlllblllZlr 'tion with a'brake cylinder,of electrically conis supplied to the brake cylinder by opera tion ofthe electrically controlled means and adapted in another position toestablish communication through which fluid under pressure is suppliedto the brake cylinder by operation of the pneumatically cont-rolledmeans, and means operative to maintain the equalized pressure of fluidfrom the brake cylinder and the pressure offluid supplied by thepneumatically controlled means below the normal pressureof fluid in thebrake pipe when communication is established between said brake cylinderand pneumatically controlled. means.

5. In a braking apparatus, the combination with a brake cylinder, ofelectrically controlled means for supplying fluid under pressure to thebrake cylinder, an auxiliary reservoir, a brake pipe, a triple valvedevice op erative upon a reduction n brake pipe pressure for supplyingfluid underpressure from said auxiliary reservoir to said brakecylinder, valve means adapted in one position to establish communicationthroughwhich flu1d under pressure is supplied to said brake cylinder bythe operation of said electrically controlled means and adapted inanother position to establish communication through which fluid underpressure is supplied to said brake. cylinder by said auxiliary reservoirthrough the operation of tlie'triple'valve device upon a reduction inbrake pipe pressure, and means operative to reduce the equalizedauxiliary and brake cylinder pressure when said brake cylinder andauxiliary reservoir are in communication.

6. In a braking apparatus, thecombination with a brake cylinder, ofelectrically controlled means for supplying fluid under pressure to thebrake cylinder, pneumatically controlled means for supplying fluid underpressure to the brake cylinder, saidipneumatically controlled meanscomprising a triple valve device, a valve device adapted in one positionI to establish communication through which fluid under pressure issupplied to the brake cylinder by operation or said electricallycontrolled means and adapted in another: posi-,. tion to establishcommunication through which fluid under pressure is supplied to thebrake cylinder by operation of said pneumatically controlled means,valve means adapted in one position to establish communication. throughwhich fluid under pressure is supplied to the brake cylinder byoperation of the electrically controlled means, and adapted in anotherposition to establish communication through which fluid under pressureis ventedeto the atmosphere, and means inde pendent of said triple valvedevice operative to control the movement of said valve means .to ventthe brake cylinder to the atmosphere when said pneumatically.controlledmeans are operated to supply fluid under pressure to the brake cylinder.

7. Inabraking apparatus, the combination with a" brake cylinder, ofelectrically controlled means for supplying fluid under pressure ,to thebrake cylinder, pneumatically controlled means for supplying fluid underpressure to-the brake cylinder, a valve adapted in one position toestablish communication through which fluid under pressure is suppliedto said brake; cylinder by the operation ofzsaid electrically controlledmeans and adapted in another position'to establish communication throughwhich fluid under pressure from the brake cylinder is vented to theatmosphere, pistons for operating said valve, a brake pipe, the pressureof fluid on both pistons beinggnormally controlled by said electricallycontrolled meansand theipressure onone ofsaid pistons being'controlledby a reduction in brake pipe pressure in effecting the operation ofthepneuinatically controlled means to supply fluid under pressure to thebrake cylinder. V

8. In a braking apparatuS the combination with a brake cylinder, of"electrically controlled means .for supplying fluid under pressure tothe brake cylinder, pneumatically controlled means forv supplying fluidunder pressure to the-brake cylinder, a valve adapted in one position toestablish communication through which fluid under pressure is suppliedto said brake cylinder by the operation of said electrically controlledmeans and adapted in another position to establish communication throughwhich fluid under pressure from the brake cylinder is vented to theatmosphere, pistons for operating said valve, a brake pipe, the pressureof fluid on both pistons being normally controlled by said electricallycontrolled means, and valve means operative upon a reduction in brakepipepressure, in eifecting the operation of said pneumaticallycontrolled means to supply fluid under pressure to the brake cylinder,

for venting fluid under pressure acting on one of said pistons to theatmosphere.

with a brake cylinder, of electrically controlled means for supplyingfluid under pressure to the brake cylinder, pneuniaticall controlledmeans for supplying fluid under pressure to the brake cylinder, a valveadapt ed in one position to establish communication through which fluidunder pressure is supplied to said brake cylinder by the operatlon ofsaid electrically controlled means and adapted in another position toestablish communication through which fluid under pressure from thebrake cylinder is vented to the atmosphere, pistons for operating saidvalve, a brake pipe, the pressure of fluid on both pistons beingnormally controlled by said electrically controlled means, and valvemeans operative upon a reduction in brake pipe pressure for ventingfluid under pressure from the chamber containing one of said pistonsuntil said valve establishes co nmunif cation through which fluid underpressure in said brake cylinder is vented to the atmosphere.

10. In a braking apparatus, the combination With a brake cylinder, ofelectrically controlled means for supplying fluid under pressure to thebrake cylinder, pneumatically controlled means for supplying fluid underpressure to the brake cylinder, a valve adapted in one position toestablish communication through which fluid under pressure is suppliedto said brake cylinder by the operation of said electrically controlledmeans and adapted in another position to establish communication throughwhich fluid under pressure from the brake cylinder is vented to theatmosphere, pistons for operating said valve,

a brake pipe, the pressure of fluid on both pistons being electricallycontrolled means, and valve means subject to the pressure of fluid fromthe brake pipe for controlling the pressure of fluid on one of saidpistons.

' 11. In a braking apparatus, the combination with a brake cylinder, ofelectrically controlled means for supplying fluid under pressure to thebrake cylinder, pneumatically controlled means for supplying fluid underpressure to the brake cylinderya valve adapted in one position toestablish communication through which fluid under pressure is suppliedto said brake cylinder by the operation of said electrically controlledmeans and adapted in another position to establish communication throughWhich fluid under pressure from the brake cylinder is vented to theatmosphere, pistons for operating said valve,-

a brake pipe, the pressure of fluid on'both pistons being normallycontrolled by said 'electrically controlled means, and valve meanssubject to pressure or fluid from the,

brake pipe for at one time reducing the presnormally controlled by saidsure acting on one of said pistons and for at another time admittingfluid under pressure 9. In a braking apparatus, the combination to saidpiston.

12. In a braking apparatus, the c0mbination with a brake cylinder,-ofelectrically con trolled means torsupplying fluid under pressure to thebrake cylinder, a triple valve de- 106 operative to supply fluid underpressure to the brake cylinder, a. brake pipe, valve means normallymaintained in a position to establish communication through which fluidunder pressure is supplied to the brake cylinder by the operation ofsaid electrically controlled means, and means separate from said triplevalve device operative upon a reduction in brake pipe pressure forcontrolling the operation of said means to close oil the supply of fluidunder pressure to thebrake cylinder and establish through which fluidunder pressure in the brake cyllnder 1s vented to permit fluid underpressure to be supplied to the brake cylin'der by the operation of saidtriple valve device.

tion-With a brake cylinder, of electrically controlled meansoperativeupon deenergization to supply fluid'under pressure to saidbrake cylinder, a valve device adapted in one position to establishcommunication through which fluid under pressure is supplied to saidbrake cylinder by the operation of said electrio-ally controlled means,a brake pipe, a triple valve device supplied With fluid under pressurefrom said brake pipe and operative upon a reduction in brake pipepressure to supply fluid under pressure to said brake cylinder, meansoperative independently of said triple valve upon a reduction in brakepipe pressure for controlling the operation of said.

valve means toa position to establish com munication through which fluidunder'pressure in the brake cylinder is vented to the atmosphere, and avalve subject to the pressure or fluid supplied by the operation of saidwhich fluid under pressure is supplied to said brake cylinder by theoperation of said electrically controlled means, a brake pipe, a triplevalve device supplied With fluid under pressure from said brake pipe andoperative upon reduction in brake p1pe pressure to supply fluid underpressureto said brake cylinder, means operative independently of saidtriple valve upon a reduction in brake plpe communication 13. In abraking apparatus, the combina fluid supplied pressure for controllingthe operation of said valve means to a position to establish com,-n'iunication through which fluid under pressure in thefbrake cylinder isvented to the atmosphere, a valve subject to-the pressure of by theoperation of said triple valve device for closing ofi the lastmentionedcommunication and establishing communication through which the fluidunder pressure remaining in said brake cylinder and that I supplied bythe operation of said triple valve device \vill equalize,

andmeans for reducing the equahzed pressure to a predetermined degreebelow the normal brake pipe pressure.

15.111 :1 braking apparatus, the combination with means for controllingthe brakes electrically and means for controlling the brakespneumatically, the last mentioned means comprising, a brake pipe and atriple valve device, valve means operative to change thecontrol oi thebrake from electric to pneumatic and means independent of said triplevalve device operative upon a reduction 1n brake pipe pressure forcontrolling the oper ation of said valve means. v

In testimony whereof I have hereunto set my hand. V

. I MILLARD C. ROlVLEY.

